Omega-cycloalkyl 17-heteroaryl prostaglandin E2 analogs as EP2-receptor agonists

ABSTRACT

The invention relates to the use of derivatives of E-type prostaglandins as EP 2  agonists, in general, and, in particular as ocular hypotensives. The PGE derivatives used in accordance with the invention are represented by the following formula I:  
                 
 
     wherein the hatched segment represents an α bonds, the solid triangle represents a β bond, the wavy segments represent α or β bond, dashed lines represent a double bond or a single bond, X is selected from the group consisting of hydrogen and halogen radicals, R 3  is heteroaryl or a substituted heteroaryl radical, R 1  and R 2  are independently selected from the group consisting of hydrogen or a lower alkyl radical having up to six carbon atoms, or a lower acyl radical having up to six carbon atoms, R is selected from the group consisting of CO 2 R 4 , CONR 4   2 , CH 2 OR 4 , CONR 4 SO 2 R 4 , P(O)(OR 4 ) and  
                 
 
     wherein R 4  is selected from the group consisting of H, phenyl and lower alkyl having from one to six carbon atoms and n is 0 or an integer of from 1 to 4.

[0001] This application is based on, and claims the benefit of, U.S.Provisional Application No. 60/338,838, filed Nov. 5, 2001.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to ω-cycloalkyl 17-heteroarylprostaglandin E₂ analogs as EP₂-receptor agonists. These compounds arepotent ocular hypotensive and are particularly suited for the managementof glaucoma.

[0004] 2. Description of Related Art

[0005] Ocular hypotensive agents are useful in the treatment of a numberof various ocular hypertensive conditions, such as post-surgical andpost-laser trabeculectomy ocular hypertensive episodes, glaucoma, and aspresurgical adjuncts.

[0006] Glaucoma is a disease of the eye characterized by increasedintraocular pressure. On the basis of its etiology, glaucoma has beenclassified as primary or secondary. For example, primary glaucoma inadults (congenital glaucoma) may be either open-angle or acute orchronic angle-closure. Secondary glaucoma results from pre-existingocular diseases such as uveitis, intraocular tumor or an enlargedcataract.

[0007] The underlying causes of primary glaucoma are not yet known. Theincreased intraocular tension is due to the obstruction of aqueous humoroutflow. In chronic open-angle glaucoma, the anterior chamber and itsanatomic structures appear normal, but drainage of the aqueous humor isimpeded. In acute or chronic angle-closure angle-closure glaucoma, theanterior chamber is shallow, the filtration angle is narrowed, and theiris may obstruct the trabecular meshwork at the entrance of the canalof Schlemm. Dilation of the pupil may push the root of the iris forwardagainst the angle, and may produce pupilary block and thus precipitatean acute attack. Eyes with narrow anterior chamber angles arepredisposed to acute angle-closure glaucoma attacks of various degreesof severity.

[0008] Secondary glaucoma is caused by any interference with the flow ofaqueous humor from the posterior chamber into the anterior chamber andsubsequently, into the canal of Schlemm. Inflammatory disease of theanterior segment may prevent aqueous escape by causing completeposterior synechia in iris bombe, and may plug the drainage channel withexudates. Other common causes are intraocular tumors, enlargedcataracts, central retinal vein occlusion, trauma to the eye, operativeprocedures and intraocular hemorrhage.

[0009] Considering all types together, glaucoma occurs in about 2% ofall persons over the age of 40 and may be asymptotic for years beforeprogressing to rapid loss of vision. In cases where surgery is notindicated, topical β-adrenoreceptor antagonists have traditionally beenthe drugs of choice for treating glaucoma.

[0010] Certain eicosanoids and their derivatives have been reported topossess ocular hypotensive activity, and have been recommended for usein glaucoma management. Eicosanoids and derivatives include numerousbiologically important compounds such as prostaglandins and theirderivatives. Prostaglandins can be described as derivatives ofprostanoic acid which have the following structural formula:

[0011] Various types of prostaglandins are known, depending on thestructure and substituents carried on the alicyclic ring of theprostanoic acid skeleton. Further classification is based on the numberof unsaturated bonds in the side chain indicated by numerical subscriptsafter the generic type of prostaglandin [e.g. prostaglandin E₁ (PGE₁),prostaglandin E₂ (PGE₂)], and on the configuration of the substituentson the alicyclic ring indicated by α or β [e.g. prostaglandinF_(2α)(PGF_(2α))].

[0012] Prostaglandins were earlier regarded as potent ocularhypertensives, however, evidence accumulated in the last decade showsthat some prostaglandins are highly effective ocular hypotensive agents,and are ideally suited for the long-term medical management of glaucoma(see, for example, Bito, L. Z. Biological Protection withProstaglandins, Cohen, M. M., ed., Boca Raton, Fla, CRC Press Inc.,1985, pp. 231-252; and Bito, L. Z., Applied Pharmacology in the MedicalTreatment of Glaucomas Drance, S. M. and Neufeld, A. H. eds., New York,Grune & Stratton, 1984, pp. 477-505. Such prostaglandins includePGF_(2α), PGF_(1α), PGE₂, and certain lipid-soluble esters, such as C₁to C₂ alkyl esters, e.g. 1-isopropyl ester, of such compounds.

[0013] Although the precise mechanism is not yet known experimentalresults indicate that the prostaglandin-induced reduction in intraocularpressure results from increased uveoscleral outflow [Nilsson et.al.,Invest. Ophthalmol. Vis. Sci. (suppl), 284 (1987)].

[0014] The isopropyl ester of PGF_(2α)has been shown to havesignificantly greater hypotensive potency than the parent compound,presumably as a result of its more effective penetration through thecornea. In 1987, this compound was described as “the most potent ocularhypotensive agent ever reported” [see, for example, Bito, L. Z., Arch.Ophthalmol. 105, 1036 (1987), and Siebold et.al., Prodrug 5 3 (1989)].

[0015] Whereas prostaglandins appear to be devoid of significantintraocular side effects, ocular surface (conjunctival) hyperemia andforeign-body sensation have been consistently associated with thetopical ocular use of such compounds, in particular PGF_(2α)and itsprodrugs, e.g., its 1-isopropyl ester, in humans. The clinicalpotentials of prostaglandins in the management of conditions associatedwith increased ocular pressure, e.g. glaucoma are greatly limited bythese side effects.

[0016] In a series of co-pending United States patent applicationsassigned to Allergan, Inc. prostaglandin esters with increased ocularhypotensive activity accompanied with no or substantially reducedside-effects are disclosed. The co-pending U.S. Ser. No. 596,430 (filedOct. 10, 1990), now U.S. Pat. No. 5,446,041, relates to certain11-acyl-prostaglandins, such as 11-pivaloyl, 11-acetyl, 11-isobutyryl,11-valeryl, and 11-isovaleryl PGF_(2α). Intraocular pressure reducing15-acyl prostaglandins are disclosed in the co-pending application U.S.Ser. No. 175,476 (filed Dec. 29, 1993). Similarly, 11,15- 9,15- and9,11-diesters of prostaglandins, for example 11,15-dipivaloylPGF_(2α)are known to have ocular hypotensive activity. See theco-pending patent applications U.S. Ser. No. Nos. 385,645 (filed Jul.07, 1989, now U.S. Pat. No. 4,994,274), 584,370 (filed Sep. 18, 1990,now U.S. Pat. No. 5,028,624) and 585,284 (filed Sep. 18, 1990, now U.S.Pat. No. 5,034,413). The disclosures of all of these patent applicationsare hereby expressly incorporated by reference.

SUMMARY OF THE INVENTION

[0017] The present invention concerns a method of treating ocularhypertension which comprises administering to a mammal having ocularhypertension a therapeutically effective amount of a compound of formulaI

[0018] wherein the hatched segment represents an α bond, the solidtriangle represents a β bond, the wavy segment represents α or β bond,dashed lines represent a double bond or a single bond, X is hydrogen ora halo radical, e.g. a fluoro or chloro radical, R³ is heteroaryl or asubstituted heteroaryl radical, R¹ and R² are independently selectedfrom the group consisting of hydrogen or a lower alkyl radical having upto six carbon atoms, or a lower acyl radical having up to six carbonatoms, R is selected from the group consisting of CO₂R⁴, CONR⁴ ₂,CH₂OR⁴, CONR⁴SO₂R⁴, P(O)(OR⁴) and

[0019] wherein R⁴ is selected from the group consisting of H, phenyl andlower alkyl having from one to six carbon atoms and n is 0 or an integerof from 1 to 4.

[0020] In a further aspect, the present invention relates to anophthalmic solution comprising a therapeutically effective amount of acompound of formula (I), wherein the symbols have the above meanings, ora pharmaceutically acceptable salt thereof, in admixture with anon-toxic, ophthalmically acceptable liquid vehicle, packaged in acontainer suitable for metered application. In particular, thesubstituents on the heteroaryl radical may be selected from the groupconsisting of lower alkyl, e.g. C₁ to C₆ alkyl; OR⁴; CO₂R⁴; halogen,e.g. fluoro, chloro and bromo; trifluoromethyl (CF₃); COR⁴, e.g.COCH_(3;) COCF_(3;) SO₂NR⁴, e.g. SO₂NH_(2;) NO_(2;) CN; etc.

[0021] In a still further aspect, the present invention relates to apharmaceutical product, comprising

[0022] a container adapted to dispense its contents in a metered form;and

[0023] an ophthalmic solution therein, as hereinabove defined.

[0024] Finally, certain of the compounds represented by the aboveformula, disclosed below and utilized in the method of the presentinvention are novel and unobvious.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0025]FIG. 1 is a schematic of the chemical synthesis of certaincompounds related to the compounds of the invention, as specificallydisclosed in Examples 12H and L and 13H and L.

[0026]FIG. 2 is a schematic of the chemical synthesis of certaincompounds related to the compounds of the invention, as specificallydisclosed in Examples 16H and L and 17H and L.

DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention relates to the use of ω-cycloalkyl17-heteroaryl prostaglandin E₂ analogs as EP₂-receptor agonists. Thecompounds used in accordance with the present invention are encompassedby the following structural formula I:

[0028] wherein the substituents and symbols are as hereinabove defined.The dotted lines on bonds between carbons 5 and 6 (C-5) and carbons 13and 14 (C-13) indicate a single or double bond. If two solid lines areused at C-5, or C-13, it indicates a specific configuration for thatdouble bond. Hatched lines used at position C-8, C-9 and C-11 indicatethe α configuration. A triangle at position C-12 represents βorientation.

[0029] A preferred group of the compounds of the present inventionincludes compounds that have the following structural formula II:

[0030] wherein Z is selected from the group consisting of O and S, A isselected from the group consisting of N, —CH, and C, R⁵ is selected fromthe group consisting of hydrogen, halogen, lower alkyl having from 1 to6 carbon atoms and lower alkoxy having from 1 to 6 carbon atoms, R⁶ andR⁷ are selected from the group consisting of hydrogen, halogen, loweralkyl having from 1 to 6 carbon atoms and lower alkoxy having from 1 to6 carbon atoms, or, together with

[0031] , R⁶ and R⁷ forms a condensed aryl ring.

[0032] Another preferred group includes compounds having the formulaIII:

[0033] In the above formulae, the substituents and symbols are ashereinabove defined.

[0034] The above compounds of the present invention may be prepared bymethods that are known in the art or according to the working examplesbelow.

[0035] The compounds, below, are especially preferred representative ofthe compounds of the present invention.

[0036]7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-5-chloro-cyclopentyl}hept-5-enoicacid methyl ester

[0037]7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methylcyclobutyl)but-1-enyl]-5-chlorocyclopentyl}hept-5-enoicacid methyl ester

[0038](Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methylcyclobutyl)but-1-enyl]-5-fluoro-cyclopentyl}hept-5-enoicacid methyl ester

[0039](Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-5-fluoro-cyclopentyl}hept-5-enoicacid

[0040](Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methylcyclobutyl)but-1-enyl]cyclopentenyl}hept-5-enoicacid methyl ester

[0041](Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2yl-methylcyclobutyl)but-1-enyl]cyclopentenyl}hept-5-enoicacid

[0042] A pharmaceutically acceptable salt is any salt which retains theactivity of the parent compound and does not impart any deleterious orundesirable effect on the subject to whom it is administered and in thecontext in which it is administered. Of particular interest are saltsformed with inorganic ions, such as sodium, potassium, calcium,magnesium and zinc.

[0043] Pharmaceutical compositions may be prepared by combining atherapeutically effective amount of at least one compound according tothe present invention, or a pharmaceutically acceptable acid additionsalt thereof, as an active ingredient, with conventional ophthalmicallyacceptable pharmaceutical excipients, and by preparation of unit dosageforms suitable for topical ocular use. The therapeutically efficientamount typically is between about 0.0001 and about 5% (w/v), preferablyabout 0.001 to about 1.0% (w/v) in liquid formulations.

[0044] For ophthalmic application, preferably solutions are preparedusing a physiological saline solution as a major vehicle. The pH of suchophthalmic solutions should preferably be maintained between 6.5 and 7.2with an appropriate buffer system. The formulations may also containconventional, pharmaceutically acceptable preservatives, stabilizers andsurfactants.

[0045] Preferred preservatives that may be used in the pharmaceuticalcompositions of the present invention include, but are not limited to,benzalkonium chloride, chlorobutanol, thimerosal, phenylmercuric acetateand phenylmercuric nitrate. A preferred surfactant is, for example,Tween 80. Likewise, various preferred vehicles may be used in theophthalmic preparations of the present invention. These vehiclesinclude, but are not limited to, polyvinyl alcohol, povidone,hydroxypropyl methyl cellulose, poloxamers, carboxymethyl cellulose,hydroxyethyl cellulose and purified water.

[0046] Tonicity adjustors may be added as needed or convenient. Theyinclude, but are not limited to, salts, particularly sodium chloride,potassium chloride, mannitol and glycerin, or any other suitableophthalmically acceptable tonicity adjustor.

[0047] Various buffers and means for adjusting pH may be used so long asthe resulting preparation is ophthalmically acceptable. Accordingly,buffers include acetate buffers, citrate buffers, phosphate buffers andborate buffers. Acids or bases may be used to adjust the pH of theseformulations as needed.

[0048] In a similar vein, an ophthalmically acceptable antioxidant foruse in the present invention includes, but is not limited to, sodiummetabisulfite, sodium thiosulfate, acetylcysteine, butylatedhydroxyanisole and butylated hydroxytoluene.

[0049] Other excipient components which may be included in theophthalmic preparations are chelating agents. The preferred chelatingagent is edentate disodium, although other chelating agents may also beused in place or in conjunction with it.

[0050] The ingredients are usually used in the following amounts:Ingredient Amount (% w/v) active ingredient about 0.001-5 preservative  0-0.10 vehicle   0-40 tonicity adjustor   1-10 buffer 0.01-10 pHadjustor q.s. pH 4.5-7.5 antioxidant as needed surfactant as neededpurified water as needed to make 100%

[0051] The actual dose of the active compounds of the present inventiondepends on the specific compound, and on the condition to be treated;the selection of the appropriate dose is well within the knowledge ofthe skilled artisan.

[0052] The ophthalmic formulations of the present invention areconveniently packaged in forms suitable for metered application, such asin containers equipped with a dropper, to facilitate the application tothe eye. Containers suitable for dropwise application are usually madeof suitable inert, non-toxic plastic material, and generally containbetween about 0.5 and about 15 ml solution.

[0053] The invention is further illustrated by the followingnon-limiting Examples, which are summarized in the reaction schemes ofFIGS. 1 and 2, wherein the compounds are identified by the samedesignator in both the Examples and the Figures.

EXAMPLE 1

[0054] Ethyl cyclobutanecarboxylate acid ethyl ester (1).

[0055] The named compound was purchased from Aldrich Chemical Co., P.O.Box 2060, Milwaukee, Wis. 53201 USA.

EXAMPLE 2

[0056] 1-(1-Hydroxy-1-thiophen-2-yl-methyl)cyclobutanecarboxylic acidethyl ester (2).

[0057] Lithium diisopropylamide mono(THF) (1.95 mL of a 2.0M solution inheptane/THF/ethylbenzene, 3.90 mmol) was added to a solution of ester 1(0.50 g, 3.9 mmol) in THF (6 mL) at −78° C. After stirring 30 min,2-thiophenecarboxaldehyde (667 mg, 5.95 mmol) was added and the mixturewas stirred for 3 h. After the reaction was judged complete by TLCanalysis, saturated aqueous NH₄Cl was added and the reaction was slowlywarmed to 23° C. The THF was evaporated and the reaction mixture wasextracted with CH₂Cl₂(2×). The combined organic layers were washed withbrine, dried (Na₂SO₄), filtered and concentrated in vacuo. Purificationof the residue by flash column chromatography (FCC) (silica gel, 100%hexane followed by 9:1 hexane/EtOAc) afforded the above named compound2.

EXAMPLE 3

[0058] 1-Thiophen-2-yl-methylcyclobutanecarboxylic acid ethyl ester (3).

[0059] Trimethylsilyliodide (20 g, 100 mmol) was added to CH₃CN (10 mL)at 0° C. and the mixture was allowed to stir 5 min. A solution ofalcohol 2 (5 g, 20 mmol) in CH₃CN (10 mL) was added slowly while thetemperature was kept between 4-10° C. and the reaction was allowed towarm to 23° C. After stirring for 2 h at 23° C. the reaction was judgedcomplete via TLC analysis. The mixture was poured into 3N NaOH at 0° C.and EtOAc was added. The organic layer was separated, washed with brine,dried (Na₂SO₄), filtered and concentrated in vacuo. FCC (silica gel, 1:1hexane/CH₂Cl₂) gave 2.3 g of the above named ester 3.

EXAMPLE 4

[0060] (1-Thiophen-2-yl-methylcyclobutyl)methanol (4).

[0061] Lithium borohydride (435 mg, 20 mmol) was added to a solution ofester 3 (2.3 g, 10 mmol) in Et₂O (20 mL) at 0° C. After having stirredfor 5 min, MeOH (640 mg, 20 mmol) was added dropwise and stirringcontinued at 0° C. until effervescence ceased. The mixture was warmed to23° C. and was allowed to stir an additional hour, at which time themixture was poured into 3N NaOH and stirred an additional 0.5 h. Theorganic layer was separated and washed with brine, dried (Na₂SO₄),filtered and concentrated in vacuo. The crude alcohol 4 was purified byFCC (silica gel, 1:1 hexane/CH₂Cl₂).

EXAMPLE 5

[0062] 1-Thiophen-2-yl-methylcyclobutanecarbaldehyde (5).

[0063] Oxalyl chloride (50 mL, 0.10 mmol) was added to CH₂Cl₂ (150 mL)at 23° C. and was cooled to −78° C. DMSO (16 g, 0.20 mmol) was addeddropwise to the mixture and stirring was continued for 15 min. Asolution of alcohol 4 (7.9 g, 0.041 mmol) in CH₂Cl₂ (50 mL) was thenadded dropwise, after which Et₃N (44 g, 0.44 mmol) was added and themixture was warmed to 23° C. After 1 h, the mixture was poured intosaturated aqueous NaHCO₃ and the organic layer was separated. Theaqueous layer was extracted with CH₂Cl₂ (2×) and the combined organicportions were washed with brine, dried (Na₂SO₄), concentrated in vacuoand purified by FCC (silica gel, 100% hexane followed by 2:1hexane/CH₂Cl₂) to afford the above named aldehyde 5.

EXAMPLE 6

[0064] 1-(1-Thiophen-2-yl-methylcyclobutyl)but-2-yn-1-ol (6).

[0065] A solution of propylmagnesium bromide (360 mL of a 0.5M solutionin THF, 0.180 mmol; 0.5 M in THF) was added dropwise to a solution ofaldehyde 5 (7.0 g, 36 mmol) in THF (200 mL) while the mixture wasmaintained at ambient temperature. After having stirred 3 h at 23° C.,the reaction was poured into saturated aqueous NH₄Cl and extracted withEt₂O. The organic portion was separated and was washed with saturatedaqueous NaHCO₃, brine, then dried (Na₂SO₄) and concentrated in vacuo.FCC (silica gel, 100% hexane followed by 1:1, hexane/CH₂Cl₂) gave 6.2 gof the above named alkyne 6.

EXAMPLE 7

[0066] 1-(1-Thiophen-2-yl-methylcyclobutyl)but-3-yn-1-ol (7).

[0067] A dry round bottom flask was charged with potassium hydride (5.5g, 48 mmol; 35% by wt dispersion in oil) and the oil was removed byhexane rinse (3×). Aminopropylamide (39 mL) was added to the mixture andit was stirred until effervescence ceased. The mixture was then cooledto 0° C. and the alkyne 6 (2 g, 9.1 mmol) was added and the reactionstirred at 23° C. for 1 h. The reaction was quenched with MeOH (2 mL)and water. The mixture was extracted with Et₂O (3×) and the combinedorganic layer was washed with 1N HCl, brine, dried (Na₂SO₄) andconcentrated in vacuo. FCC (silica gel, 1:1 hexane/CH₂Cl₂) gave 570 mgof the above named alkyne 7.

EXAMPLE 8

[0068] tert-Butyldimethyl[1-(1-thiophen-2-yl-methylcyclobutyl)but-3-ynyloxy]silane (8).

[0069] To a cooled (0° C.) solution of alkyne 7 (200 mg, 0.9 mmol),CH₂Cl₂ (5 mL) and triethylamine (275 mg, 2.72 mmol) was addedtert-butyldimethylsilyl trifluoromethanesulfonate (360 mg, 1.36 mmol)dropwise. After having stirred for 5 min at 0° C., the mixture waswarmed to 23° C. and stirred an additional hour. The reaction was thenquenched with saturated aqueous NaHCO₃ and extracted with CH₂Cl₂ (2×).The combined organics were washed with 1N HCl, saturated aqueous NaHCO₃,brine then were dried (Na₂SO₄), filtered and concentrated in vacuo. FCC(silica gel, 100% hexane) gave 695 mg of the above named compound 8.

EXAMPLE 9

[0070]tert-Butyl-[(E)-4-iodo-1-(1-thiophen-2-ylmethylcyclobutyl)but-3-enyloxy]dimethylsilane(9).

[0071] Cp₂ZrHCl (304 mg, 1.18 mmol) was added to a solution of alkyne 8(263 mg, 0.786 mmol) in CH₂Cl₂ (5 mL) at 23° C. and stirring wasmaintained for 20 min. N-iodosuccinimide (247 mg, 1.18 mmol) was addedto the mixture and stirring was continued for an additional 30 min. Themixture was concentrated in vacuo, diluted with hexane/Et₂O, filteredand concentrated in vacuo. FCC (silica gel, 100% hexane) gave 360 mg ofthe above named compound 9.

EXAMPLE 10

[0072]7-[(R)-3-(tert-Butyldimethylsilanyloxy)-5-oxo-cyclopent-1-enyl]heptanoicacid methyl ester (10).

[0073] The named compound was purchased from Nissan Chemical Industries,LTD, Tokyo 101-0054 Japan.

EXAMPLE 11

[0074]7-{(1R,2R,3R)-2-[(E)-(tert-Butyldimethylsilanyloxy)-(1-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-3-[(dimethylethyl)dimethylsilanyloxy]-5-oxo-cyclopentyl}heptanoicacid methyl ester (11).

[0075] To a solution of vinyl iodide 9 (120 mg, 0.259 mmol) in Et₂O (1.5mL) at −78° C. was added t-BuLi (0.35 mL of a 1.5M solution in THF, 0.52mmol). After the mixture had stirred 30 min at −78° C.2-thienyl(cyano)copper lithium (1.14 mL, 0.285 mmol) was added andstirring was continued for an additional 30 min. The reaction was thentreated with a solution of the enone 10 (91.6 mg, 0.259 mmol) in Et₂O (1mL). After several minutes had passed, the reaction had solidified and0.5 mL Et₂O was added. The reaction was stirred 1 h at −78° C., waspoured into saturated aqueous NH₄Cl and then was extracted with EtOAc(3×). The combined organic portions were washed with brine, filtered andconcentrated in vacuo. FCC (silica gel, 100% hexane; 9:1 hexane/EtOAc)gave 63 mg of the above named compound 11.

EXAMPLE 12

[0076]7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methyl-cyclobutyl)but-1-enyl]-5-oxo-cyclopentyl}heptanoicacid methyl ester (12H).

[0077]7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methyl-cyclobutyl)but-1-enyl]-5-oxo-cyclopentyl}heptanoicacid methyl ester (12L).

[0078] Hydrogen fluoride-pyridine (0.091 mL) was added to a solution ofthe bis-TBS ether 11 (63 mg, 0.912 mmol) in CH₃CN (3 mL) at 23° C. Afterhaving stirred for 3 h, the mixture was quenched with saturated aqueousNa₂CO₃ and extracted with EtOAc (3×). The combined organic portions werewashed with 1N HCl, saturated aqueous NaHCO₃, brine, and were then dried(Na₂SO₄), filtered and concentrated in vacuo. FCC (silica gel, 3:2hexane/EtOAc followed by 1:1 hexane/EtOAc) gave a higher R_(f) diol (10mg) and a lower R_(f) diol (30 mg), hereinafter, designated as namedcompounds 12H and 12L, respectively).

EXAMPLE 13H

[0079]7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-5-oxocyclopentyl}heptanoicacid (13H).

[0080] Methyl ester 12H (4.8 mg, 10.4 mmol) and PLE (0.134 mmol, 45mmol) were stirred in phosphate buffer (2 mL, pH 7.2) at 23° C. over 16h. After the reaction was complete, the mixture was filtered and theaqueous phase was extracted with EtOAc (3×). The combined organic phaseswere washed with brine, dried (Na₂SO₄), filtered and concentrated invacuo. FCC (silica gel, 1:1 hexane/EtOAc; EtOAc) gave of the above namedacid 13H.

EXAMPLE 13L

[0081]7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methyl-cyclobutyl)but-1-enyl]-5-oxo-cyclopentyl}heptanoicacid (13L).

[0082] Methyl ester 12L was reacted according to Example 13H to yieldthe above named compound.

EXAMPLE 14

[0083](Z)-7-[(R)-3-(tert-Butyldimethylsilanyloxy)-5-oxo-cyclopent-1-enyl]hept-5-enoicacid methyl ester (14).

[0084] The named compound was purchased from Nissan Chemical Industries,LTD, Tokyo 101-0054 Japan.

EXAMPLE 15

[0085](Z)-7-{(1R,2R,3R)-2-[(E)-(tert-Butyldimethylsilanyloxy)-(1-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-3-[(dimethylethyl)dimethylsilanyloxyl-5-oxo-cyclopentyl}hept-5-enoic acid methyl ester (15).

[0086] The compound of Example 14, above, was reacted in accordance withthe process of Example 11 to yield the above named compound.

EXAMPLE 16

[0087](Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-5-oxo-cyclopentyl}hept-5-enoicacid methyl ester (16H).

[0088](Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-5-oxo-cyclopentyl}hept-5-enoicacid methyl ester (16L).

[0089] The compound of Example 15 is reacted in accordance with theprocess of Example 12 to yield a higher R_(f) diol (6.0 mg) and a lowerR_(f) diol (6.0 mg), hereinafter, designated as 16H and 16L,respectively.

EXAMPLE 17H

[0090](Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-5-oxo-cyclopentyl}hept-5-enoicacid (17H).

[0091] The compound 16H of Example 16 is reacted in accordance with theprocess of Example 13H to yield the above named compound.

EXAMPLE 17L

[0092](Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-5-oxo-cyclopentyl}hept-5-enoicacid (17L).

[0093] The compound 16L of Example 16 is reacted in accordance with theprocess of Example 13H to yield the above named compound.

EXAMPLE 18

[0094]7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-5-chloro-cyclopentyl}hept-5-enoicacid methyl ester (18H and 18L).

[0095] Examples 14 through 16 is repeated with the appropriate chloroderivative replacing(Z)-7-[(R)-3-(tert-Butyldimethylsilanyloxy)-5-oxo-cyclopent-1-enyl]hept-5-enoicacid methyl ester 14 and the appropriate chlorothienyl derivativereplacing 2-thienyl(cyano)copper lithium to yield a product which isseparated to provide a higher R_(f) diol and a lower R_(f) dioldesignated as 18H and 18L, respectively.

EXAMPLE 19H

[0096]7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-5-chloro-cyclopentyl}hept-5-enoicacid (19H).

[0097] The compound of Example 18H is reacted according to the processof Example 13H to yield the named compound.

EXAMPLE 19L

[0098]7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-5-chloro-cyclopentyl}hept-5-enoicacid (19L).

[0099] The compound of Example 18L is reacted according to the processof Example 13L to yield the named compound.

EXAMPLE 20

[0100]7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-5-fluoro-cyclopentyl}hept-5-enoicacid methyl ester (20H and 20L).

[0101] Examples 14 through 16 is repeated with the appropriate fluoroderivative replacing(Z)-7-[(R)-3-(tert-Butyldimethylsilanyloxy)-5-oxo-cyclopent-1-enyl]hept-5-enoicacid methyl ester 14 and the appropriate chlorothienyl derivativereplacing 2-thienyl(cyano)copper lithium to yield a product which isseparated to provide a higher R_(f) diol and a lower R_(f) dioldesignated as 20H and 20L, respectively.

EXAMPLE 21H

[0102]7-{(1R,2R,3R)-3-Hydroxy-2-](E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-5-fluoro-cyclopentyl}hept-5-enoicacid (21H).

[0103] The compound of Example 20H is reacted according to the processof Example 13H to yield the named compound.

EXAMPLE 21L

[0104]7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-5-fluoro-cyclopentyl}hept-5-enoicacid (21L).

[0105] The compound of Example 20L is reacted according to the processof Example 13L to yield the named compound.

EXAMPLE 22

[0106]7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-cyclopentenyl}hept-5-enoicacid methyl ester.

[0107] Examples 14 through 16 is repeated with the appropriate nor ketoderivative replacing(Z)-7-[(R)-3-(tert-Butyldimethylsilanyloxy)-5-oxo-cyclopent-1-enyl]hept-5-enoicacid methyl ester 14 and the appropriate chlorothienyl derivativereplacing 2-thienyl(cyano)copper lithium to yield a product which isseparated to provide a higher R_(f) diol and a lower R_(f) dioldesignated as 22H and 22L, respectively.

EXAMPLE 23H

[0108]7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-cyclopentenyl}hept-5-enoicacid (23H).

[0109] The compound of Example 22H is reacted according to the processof Example 13H to yield the named compound.

[0110] EXAMPLE 23L

[0111]7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-cyclopentenyl}hept-5-enoicacid (23L).

[0112] The compound of Example 22L is reacted according to the processof Example 13L to yield the named compound.

RADIOLIGAND BINDING

[0113] Recombinant EP₂ receptor; transient transfectants COS-7 cellswere transiently transfected using Lipofectin (Gibco-BRL lifeTechnologies, Gaitherburg, Md., U.S.A.) according to manufacturer'sprotocols. For binding studies, 2×10⁶ cells were plated onto 150 mmdishes 24 h prior to transfection.

[0114] Each plate was transfected with 50 μg plasmid DNA and 50 μLlipofectin. Cells were collected and membranes prepared at 48 hpost-transfection, and frozen at −80° C. until use.

[0115] Plasma membrane preparations were thawed at room temperature andused at a final 1 mg/mL concentration in a 500 μL volume. The binding of[³H]-PGE₂ (specific activity 180 Ci mmol⁻¹) were determined in duplicateand experiments were replicated three times. Incubations were for 60 minat 25° C. and were terminated by the addition of 4 mL of ice-cold 50 μMTRIS-HCl, followed by rapid filtration through Whatman GF/B filters andthree additional 4 mL washes in a cell harvester (Brandel). Competitionstudies were performed using a final concentration of 5 nM [³H]-PGE₂ andnon-specific binding determined with 10 μM of the respective unlabelledprostanoid.

[0116] Certain of the above compounds were tested for activity in therecombinant human EP₂ receptor assay described above and the results arereported in Table 1, below. Note Examples 20 and 21 are the unseparatedmixtures of Examples 20H and 20L and 21H and 21L, respectively. Ex- am-ple # Structure hEP₂ 18H

4300 18L

5500 19H

126 19L

300 22H

NA 22L

NA 23H

700 23L

2500 20H

5100 20L

NA 21H

132 21L

300 20

8100 21

112

[0117] EP₂ activity indicates that the compounds of this invention areuseful in treating asthma, dysmenorrhea as well as glaucoma and loweringintraocular pressure.

[0118] Other potential therapeutic applications are in osteoporosis,constipation, renal disorders, sexual dysfunction, baldness, diabetes,cancer and in disorder of immune regulation.

[0119] The compounds of the invention may also be useful in thetreatment of various pathophysiological diseases including acutemyocardial infarction, vascular thrombosis, hypertension, pulmonaryhypertension, ischemic heart disease, congestive heart failure, andangina pectoris, in which case the compounds may be administered by anymeans that effect vasodilation and thereby relieve the symptoms of thedisease. For example, administration may be by oral, transdermal,parenterial, subcutaneous, intravenous, intramuscular, intraperitoneal,transdermal, or buccal routes.

[0120] The compounds of the invention may be formulated into an ointmentcontaining about 0.10 to 10% of the active ingredient in a suitable baseof, for example, white petrolatum, mineral oil and petroatum and lanolinalcohol. Other suitable bases will be readily apparent to those skilledin the art.

[0121] The pharmaceutical preparations of the present invention aremanufactured in a manner which is itself known, for example, by means ofconventional dissolving or suspending the compounds, which are alleither water soluble or suspendable. For administration in the treatmentof the other mentioned pathophysiological disorders. The pharmaceuticalpreparations which can be used orally include push-fit capsules made ofgelatin, as well as soft, sealed capsules make of gelatin and aplasticizer such as glycerol or sorbitol. The push-fit capsules cancontain the active compounds in liquid form that may be mixed withfillers such as lactose, binders such as starches, and/or lubricantssuch as talc or magnesium stearate and, optionally, stabilizers. In softcapsules, the active compounds are preferably dissolved or suspended insuitable liquids, such as in buffered salt solution. In addition,stabilizers may be added.

[0122] In addition to being provided in a liquid form, for example ingelatin capsule or other suitable vehicle, the pharmaceuticalpreparations may contain suitable excipients to facilitate theprocessing of the active compounds into preparations that can be usedpharmaceutically. Thus, pharmaceutical preparations for oral use can beobtained by adhering the solution of the active compounds to a solidsupport, optionally grinding the resulting mixture and processing themixture of granules, after adding suitable auxiliaries, if desired ornecessary, to obtain tablets or dragee cores.

[0123] Suitable excipients are, in particular, fillers such as sugars,for example lactose or sucrose, mannitol or sorbitol, cellulosepreparations and/or calcium phosphates, for example tricalcium phosphateor calcium hydrogen phosphate, as well as inders such as starch, pasteusing for example, maize starch, wheat starch, rich starchy, potatostarch, gelatin, tragacanth, methyl cellulose,hydroxypropylmethylcellulose, sodium carboxymethylcellulose, and/orpolyvinyl pyrrolidone. If desired, disintegrating agents may be addedsuch as the above-mentioned starches and also carboxymethyl-starch,crosslinked polyvinyl pyrrolidone, agar, or algenic acid or a saltthereof, such as sodium alginate. Auxiliaries are, above all,flow-regulating agents and lubricants, for example, silica, talc,stearic acid or salts thereof, such as magnesium stearate or calciumstearate, and/or polyethylene glycol. Dragee cores are provided withsuitable coatings which if desired, are resistant to gastric juices. Forthis purpose, concentrated sugar solutions may be used, which mayoptionally containing gum arabic, talc, polyvinyl pyrrolidone,polyethylene glycol and/or titanium dioxide, lacquer solutions andsuitable organic solvents or solvent mixtures. In order to producecoatings resistant to gastric juices, solutions of suitable cellulosepreparations such as acetylcellulose phthalate orhydroxypropylmethyl-cellulose phthalate, are used. Dye stuffs orpigments may be added to the tables or dragee coatings, for example, foridentification or in order to characterize combinations of activecompound doses.

[0124] Suitable formulations for intravenous or parenteraladministration include aqueous solutions of the active compounds. Inaddition, suspensions of the active compounds as oily injectionsuspensions may be administered. Aqueous injection suspensions maycontain substances which increase the viscosity of the suspensioninclude, for example, sodium carboxymethyl cellulose, soribitol, and/ordextran. Optionally, the suspension may also contain stabilizers.

[0125] The foregoing description details specific methods andcompositions that can be employed to practice the present invention, andrepresents the best mode contemplated. However, it is apparent for oneof ordinary skill in the art that further compounds with the desiredpharmacological properties can be prepared in an analogous manner, andthat the disclosed compounds can also be obtained from differentstarting compounds via different chemical reactions. Similarly,different pharmaceutical compositions may be prepared and used withsubstantially the same result. Thus, however detailed the foregoing mayappear in text, it should not be construed as limiting the overall scopehereof, rather, the ambit of the present invention is to be governedonly by the lawful construction of the appended claims.

1. A method of treating ocular hypertension which comprisesadministering to a mammal having ocular hypertension a therapeuticallyeffective amount of a compound represented by formula I:

wherein the hatched segment represents an α bond, the solid trianglerepresents a β bond, the wavy segment represents α or β bond, dashedlines represent a double bond or a single bond, X is selected from thegroup consisting of hydrogen and halogen radicals, R³ is heteroaryl or asubstituted heteroaryl radical, R¹ and R² are independently selectedfrom the group consisting of hydrogen or a lower alkyl radical having upto six carbon atoms, or a lower acyl radical having up to six carbonatoms, R is selected from the group consisting of CO₂R⁴, CONR⁴ ₂,CH₂OR⁴, CONR⁴SO₂R⁴, P(O)(OR⁴) and

wherein R⁴ is selected from the group consisting of H, phenyl and loweralkyl having from one to six carbon atoms and n is 0 or an integer offrom 1 to
 4. 2. The method of claim 1 wherein the substituent on theheteroaryl radical is selected from the group consisting of C₁ to C₆alkyl; OR⁴; CO₂R⁴; halogen, trifluoromethyl; COR⁴; COCF₃; SO₂NR⁴, NO₂;and CN.
 3. The method of claim 2 wherein said compound is represented byformula II:

wherein Z is selected from the group consisting of O and S, A isselected from the group consisting of N, —CH, and C, R⁵ is selected fromthe group consisting of hydrogen, halogen, lower alkyl having from 1 to6 carbon atoms, and lower alkoxy having from 1 to 6 carbon atoms, R⁶ andR⁷ are selected from the group consisting of hydrogen, halogen, loweralkyl having from 1 to 6 carbon atoms, lower alkoxy having from 1 to 6carbon atoms or, together with

, R⁶ and R⁷ forms a condensed aryl ring.
 4. The method of claim 3wherein said compound is represented by formula III:


5. The method of claim 4 wherein the dashed line represents a doublebond.
 6. The method of claim 4 wherein the dashed line represents asingle bond.
 7. The method of claim 5 wherein R is CO₂R⁴ and R⁴ is H. 8.The method of claim 6 wherein R is CO₂R⁴ and R⁴ is H.
 9. The method ofclaim 5 wherein R is CO₂R⁴ and R⁴ is methyl.
 10. The method of claim 6wherein R is CO₂R⁴ and R⁴ is methyl.
 11. The method of claim 4 wherein Ris CO₂R⁴.
 12. The method of claim 11 wherein R⁴ is selected from thegroup consisting of H and lower alkyl.
 13. The method of claim 4 whereinA is C and R₅, R₆ and R₇ are H.
 14. The method of claim 1 wherein X isselected from the group consisting of hydrogen, fluoro and chlororadicals.
 15. The method of claim 14 wherein X is hydrogen.
 16. Themethod of claim 14 wherein X is fluoro.
 17. The method of claim 14wherein X is chloro.
 18. The method of claim 1 wherein said compound is7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)methyl-cyclobutyl)but-1-enyl]-5-chloro-cyclopentyl}hept-5-enoicacid methyl ester.
 19. The method of claim 1 wherein said compound is7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)methylcyclobutyl)but-1-enyl]-5-chlorocyclopentyl}hept-5-enoicacid.
 20. The method of claim 1 wherein said compound is(Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methylcyclobutyl)but-1-enyl]-5-fluoro-cyclopentyl}hept-5-enoicacid methyl ester
 21. The method of claim 1 wherein said compound is(Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-methylcyclobutyl)but-1-enyl]-5-fluoro-cyclopentyl}hept-5-enoicacid.
 22. An ophthalmic solution comprising a therapeutically effectiveamount of a compound of formula I, as defined in claim 1, or apharmaceutically acceptable salt thereof, in admixture with a non-toxic,ophthalmically acceptable liquid vehicle, packaged in a containersuitable for metered application.
 23. The ophthalmic solution of claim22 wherein said compound is a compound of Formula III.
 24. Apharmaceutical product, comprising a container adapted to dispense thecontents of said container in metered form; and an ophthalmic solutionin said container comprising a compound of formula I as defined in claim1, or a pharmaceutically acceptable salt thereof, in admixture with anon-toxic, ophthalmically acceptable liquid vehicle.
 25. The product ofclaim 24 wherein said compound is a compound of Formula III.
 26. Thecompound represented by formula I:

wherein the hatched segment represents an α bond, the solid trianglerepresents a β bond, the wavy segment represents an α or β bond, dashedlines represent a double bond or a single bond, X is selected from thegroup consisting of hydrogen and halogen radicals, R³ is heteroaryl or asubstituted heteroaryl radical, R¹ and R² are independently selectedfrom the group consisting of hydrogen or a lower alkyl radical having upto six carbon atoms, or a lower acyl radical having up to six carbonatoms, R is selected from the group consisting of CO₂R⁴, CONR⁴ ₂,CH₂OR⁴, CONR⁴SO₂R⁴, P(O)(OR⁴) and

wherein R⁴ is selected from the group consisting of H, phenyl and loweralkyl having from one to six carbon atoms and n is 0 or an integer offrom 1 to
 4. 27. The compound of claim 26 wherein R is CO₂R⁴.
 28. Thecompound of claim 27 wherein R⁴ is selected from the group consisting ofH and lower alkyl.
 29. The compound of claim 28 wherein said compound isrepresented by the formula


30. The compound of claim 29 wherein A is C and R₅, R₆ and R₇ are H. 31.The compound of claim 30 wherein said compound is selected from thegroup consisting of:7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-5-chloro-cyclopentyl}hept-5-enoicacid methyl ester,7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)methylcyclobutyl)but-1-enyl]-5-chlorocyclopentyl}hept-5-enoicacid,(Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methylcyclobutyl)but-1-enyl]-5-fluoro-cyclopentyl}hept-5-enoicacid methyl ester,(Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methylcyclobutyl)but-1-enyl]-5-fluoro-cyclopentyl}hept-5-enoicacid,(Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl-methylcyclobutyl)but-1-enyl]cyclopentenyl}hept-5-enoicacid methyl ester and(Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl-methylcyclobutyl)but-1-enyl]cyclopentenyl}hept-5-enoicacid.